In communication systems, it is generally desirable to transmit a useful signal, which contains an item of information to be transmitted, at the highest possible data rate. A high data rate can be achieved, for example, by a wide bandwidth in the transmission channel. For example, a wide bandwidth and thus a high data rate will be achieved in a radio communication system by transmitting in a wide frequency band. However, the frequency band used is not available to other users as a result. The aim is therefore to increase the efficiency of a communication system. In this case, the efficiency results from the ratio of the data rate to the bandwidth used by the communication system. In a digital radio system, this is represented, for example, by the spectral efficiency which can be stated using the variable of bits transmitted per second per hertz of bandwidth used.
Different methods can be used to increase the efficiency. So-called MIMO (Multiple Input Multiple Output) techniques are often used in mobile radio systems, for example in mobile telephones or WLAN systems. A plurality of transmitting and receiving antennas for wireless communication are used for this purpose. A transmission arrangement thus comprises a plurality of transmitting antennas.
A plurality of transmitting antennas are often also provided in a transmission arrangement for other reasons. For example, the same useful signal is fed into a communication channel via a plurality of antennas by means of so-called transmit diversity. This makes it possible, for example, to counteract effects such as fading caused by multipath propagation.
The provision of two or more transmitting antennas generally requires the provision of two or more parallel transmission paths. However, it is problematic in this case that, when two transmission paths are arranged in an electronic component, there may be crosstalk of a radio-frequency signal in one transmission path to a second transmission path, and the signal processing in the second transmission path is either more complicated or is of reduced quality as a result.